1. For y, I think that refers to the first picture attached. As you can see, each side of the triangle have the same short line drawn across it. It means that they are equal in length. That means the triangle is equilateral, which means each interior angle is 60°. Thus,
60 = 5y + 10
5y = 60 - 10
5y = 50
y = 50/5 = 10
2. As you can see in the second picture attached, Angles B and C are equal. That also means that their respective opposite sides are equal. So,
8x - 4 = 5x + 11
8x - 5x = 11 + 4
3x = 15
x = 15/3 = 5
Consequently,
BC = 4x - 2
BC = 4(5) - 2 = 18
